Question

find the area of a triangle two sides of which are 18cm and 10cm and the perimeter is 42​

Answer 1

Let ,

The required third side = C

Given ,

Perimeter of ΔABC = 42 cm

Side A = 18 cm

Side B = 10 cm

We know that ,

Perimeter Δ = sum of the all sides

Therefore ,

$\to$42 = 18 + 10 + C

$\to$42 = 28 + C

$\to$C = 42 - 28

$\to$C = 14 cm

Hence , the required value is 14 cm